What toxins are present in the venoms of black‑widow (Latrodectus) and brown‑recluse (Loxosceles) spiders?

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Toxinas de ambas

  • Araña viuda negra (Latrodectus): la toxina dominante es la α-latrotoxina (α-LTX), una neurotoxina vertebrado‑específica que induce liberación masiva de neurotransmisores mediante formación de poros y activación de receptores sinápticos (latrofilina y neurexina). 1, 2

    • Otras latrotoxinas del género (menos relevantes para humanos): latroinsectotoxinas (α/δ‑LITs) y latrocrustatoxinas; su expresión varía por tejido y estadio, mientras que α‑LTX es ubicua en Latrodectus y explica la morbilidad neurológica humana 3.

  • Araña reclusa parda (Loxosceles): la toxina principal son fosfolipasas D (PLDs), responsables de dermonecrosis y loxoscelismo sistémico (hemólisis, lesión renal). 4, 5

    • Toxinas accesorias que potencian el daño: metaloproteasas tipo astacina (degradan matriz y facilitan diseminación), hialuronidasas, serin‑proteasas, TCTP, alérgenos, serpinas y péptidos knottins (ICK) 5, 6.

  • Matiz de evidencia:

    • Para Latrodectus, α‑LTX es el determinante clave de toxicidad en vertebrados y está conservada y seleccionada purificativamente; esto se correlaciona con la clínica neurotóxica y afecta directamente morbilidad y calidad de vida 2.
    • Para Loxosceles, las PLDs reproducen por sí solas la mayoría de efectos del veneno y son el principal blanco terapéutico; otras enzimas actúan como “factores de diseminación” y modulan la gravedad del cuadro, impactando complicaciones y mortalidad 4, 5, 6.

References

1
Research

The multiple actions of black widow spider toxins and their selective use in neurosecretion studies.

Toxicon : official journal of the International Society on Toxinology, 2004

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